Cantharis (Cantharis) raeorum FANTI & M. G. PANKOWSKI, 2020

Fanti, Fabrizio & Pankowski, Maximilian G., 2020, Two new species of Cantharis Linnaeus, 1758 from Baltic amber, Zootaxa 4878 (3), pp. 401-411 : 405-409

Cantharis (Cantharis) raeorum FANTI & M. G. PANKOWSKI sp. nov.

( Figs. 4–6 )

Description. Adult, winged. Female, based on transverse, rounded shape of last ventrite. Body entirely dark brown to black. Body length: 5.8 mm; elytra 4.7 mm; antennae 4.6 mm long.

Head almost completely exposed, wide, slightly elongated anteriorly, with scattered and short setae. Eyes small, convex, prominent, inserted in the upper-lateral part of the head. Mandibles elongate, slender, falciform. Maxillary palpi 4-segmented, with first palpomere short; second palpomere elongate and robust; third palpomere globular and slightly longer than first; last palpomere robust and strongly securiform, with rounded tip. Labial palpi 3-segmented. Antennae 11-segmented, rather long, surpassing half of the elytra and not reaching the apex, filiform, adorned with some short setae plus a few other long setae especially near apices of antennomeres; scape elongate, robust, little club-shaped; antennomere II short, about 2.7–2.8 times shorter than the scape; antennomere III filiform, elongate, shorter than scape; antennomeres IV–VI sub-equal, longer than antennomere III and same length as scape; antennomeres VII–IX each very slightly shorter than previous one; antennomere X longer than antennomere IX; antennomere XI filiform, robust, rounded at apex ( Fig. 5D ). Pronotum elongate, longer than wide, narrower compared to head, equipped with scattered and long setae, anterior margin widely rounded and strongly bordered with the edge thick and apparent, lateral sides straight and bordered, posterior margin almost straight and not bordered, surface fairly flat except part adjacent to anterior margin and with transverse and concave line/part near posterior margin, all corners rounded ( Fig. 5B ). Scutellar shield triangular, very wide at base, rounded at apex. Elytra wider than pronotum, elongate, surpassing the last abdominal segment, parallel-sided, equipped with long setae, rounded apically, surface slightly rugose, sides slightly bordered especially at humeri ( Figs. 4A , 5A ). Hind wings completely covered by elytra except for apex, infuscate. Sternum subquadrate, rugose, posteriorly fairly straight ( Figs. 4B , 5C ). Abdominal ventrites transverse, slightly pubescent, last ventrite large, rounded and not triangular ( Figs. 4B , 5C , 6 ). Legs long, slender, covered with numerous long setae, pro- and mesothoracic legs short, posterior legs long; coxae robust, globular, with rounded apex; trochanters elongate, with rounded apex; femora cylindrical, slightly curved; tibiae much shorter than femora, slender, cylindrical, slightly curved. Tarsi 5-segmented equipped with long setae; first tarsomere elongate, first pro- and mesotarsomere sturdier than first metatarsomere; second tarsomere shorter than first tarsomere; third tarsomere shorter than second, strongly lobed; fourth tarsomere robust and strongly bilobed; fifth tarsomere thin and elongate; claws simple with a very small and obtuse basal tooth ( Fig. 4 ). Male unknown.

Etymology. Species named after the Rae family—aunt, uncle, and cousins of the second author—who have touched numerous lives with their love, faith, and generosity.

Holotype. Female , adult specimen in a Baltic amber piece: Catalog number MCZ: Ent:PALE-43615, in the Museum of Comparative Zoology ( MCZ) at Harvard University.

Type locality. Open pit mine (“Primorskoje”) in Yantarny (formerly Palmnicken), Baltic Sea Coast, Sambian Peninsula, Kaliningrad Region, Russia.

Type strata. Baltic amber, Eocene, Priabonian, Prussian Formation, “Blue Earth—Blaue Erde” sediment (38.0–35.6 MYA).

Syninclusions. Stellate hairs, botanical remains, gas vesicles (air bubbles), a dipteran (Nematocera: Bibionomorpha), and an unidentified insect (possibly a neanid).

Systematic placement. The securiform last maxillary palpomere, the 11-segmented antennae that are filiform, bilobed third tarsomere, and the simple claws with a small and obtuse basal tooth place the new species in the genus Cantharis and its nominotypical subgenus ( Brancucci 1980; Kazantsev 2018).

Differential diagnosis. The species that appears most closely related to Cantharis raeorum sp. nov. is Cantharis (s. str.) borki Fanti & Damgaard, 2019 , which is tinier (4.5 mm), has different antennae (in particular, the antennomere X is shorter than previous ones IV-IX in C. borki , while the antennomere X of C. raeorum sp. nov. is slightly longer than the antennomere IX), and has the pronotum that is more concave in the middle part and less concave near the posterior margin ( Fanti & Damgaard 2019). In addition, C. raeorum sp. nov. differs from Cantharis (Cyrtomoptila) sucinokotejai ( Kuśka, 1996) based on the latter species’ simple claws without a basal tooth, and the pronotum that is almost square and fairly flat near the posterior margin ( Kuśka 1996).

Remarks. The yellow amber piece has a half-moon shape, measures approximately 13 x 7 x 4 mm, and weighs 0.2 grams.The inclusion is complete and easily visible. The beetle’s head, pronotum, and legs are bent.

Figures

FIGURE 4. Cantharis (Cantharis) raeorum sp. nov. in Baltic amber. A: Holotype, dorso-lateral view, scale bar = 1.0 mm. B: Holotype, ventro-lateral view, scale bar = 1.0 mm.

FIGURE 5. Cantharis (Cantharis) raeorum sp. nov. in Baltic amber. A: Holotype, dorsal view (larger details), scale bar = 1.0 mm. B: Holotype, detail of pronotum and scutellar shield, scale bar = 0.3 mm. C: Holotype, detail of head, pronotum, metasternum, and palps (lateral view), scale bar = 0.5 mm. D: Holotype, detail of right antenna (ventral view), scale bar = 0.5 mm.

FIGURE 6. Cantharis (Cantharis) raeorum sp. nov. in Baltic amber. Holotype, detail of last ventrites, scale bar = 0.2 mm.